Thanks, liked your reply.
"The realized dzogchen practitioner, no longer deluded by apparent substantiality or dualisms such as mind and matter, releases the energy of the elements that compose the physical body at the time of death."
To me from this it would follow that all who are enlightened, realised emptiness, attains a rainbow body. Thus either nobody else is enlightened or the manifestation of rainbow body depends on something else. Maybe tögal practice creates this habit to in the end dissolve the body - just guessing.
"togal which explain how wisdom and the 5 elements have yet to be totally liberated in clear light before the fruition of that level of practice"
If it is necessary to dissolve the physical body (except hair and nails, for whatever reason) to attain maximum buddhahood it looks like to me that then being bound by the body can be overcome only through the elimination of the body (arupaloka is a strange thing then to mention).
OK lemme start by stating the obvious, that I'm getting in wayyy over my head in trying to explain this because it's so unfathomably subtle and nuanced that I can't possibly understand it yet, let alone explain it well.
That said, I must first clarify that the "rainbow body" Dzogchen is calling the supreme realization is not the one that happens when great practitioners die and they dissolve into light except for their hair and nails (and it's only the hair and nails because those are not living tissues with channels pervading them)... That realization is beyond profound, for sure, and it indicates attainment of buddhahood, but Dzogchen is talking about the "jalu phowa chenpo" or "rainbow body of great transference" which happens not at death but rather during a practitioner's life at the precise moment he or she accomplishes the 4th vision of togal wherein even the smallest traces of obscurations are liberated within clear light. In this case, death is basically bypassed. It must be understood that Dzogchen recognizes levels of buddhahood (which Anuttaryoga tantra does as well, though Dzogchen enumerates a few more with slightly more nuance).
Now, this jalu phowa chenpo does not reflect any such need to shed or dissolve the body as if it's somehow getting in the way... Dzogchen already says that for someone who has some realization of the natural state, when they die and are no longer bound within the physical body it's like a full grown garuda cracking open its shell and taking flight. That is in terms of realizing primordial purity through the practice of trekchod. So it's not that physicality is a problem (as the experience of the skandhas is really just a result of ignorance), it is that one needs to completely liberate within clear light one's primordial wisdom and the obscurations that function as causes of experiencing phenomena as other than the 5 wisdoms - as other than the energy of one's own primordial rigpa. This means one is going the distance and also completely realizing spontaneous presence, the accomplishment of togal. In other words, primordial purity is related more to the emptiness aspect and spontaneous presence more to the manifestation aspect. Anyhow, I believe this jalu phowa chenpo is just one's own inward realization, in terms of ordinary beings' perception of one, meaning they would not perceive one any differently. I'm pretty sure I remember Namdrol confirming that's what the teachings say.
In the end, honestly, I've had this stuff explained to me about ignorance being "bound by wisdom" through realization of trekchod but not completely liberated until realization of togal, but it's beyond my capacity to understand. Levels of buddhahood are beyond splitting hairs for us mere mortals (even though we're truly Guru Rinpoche). I mean if we can't possibly comprehend the realization of buddhahood as it's presented in Sutra, how are we going to fathom even more subtle distinctions of realization beyond that? It's kind of pointless speculation. The teachings just say what they say and people can either have some faith in it or suspend judgment or don't buy it (though people who have the merit to receive these teachings someday I assume would naturally have faith in them when receiving them properly from someone who knows what he/she's talking about). All I can say is that the teachings on this I've received made enough sense to me to make me feel it is the most plausible explanation I've come across and not at all some form of elitism (not that anyone hinted at that; I'm just saying).
One important thing to note is that it's my understanding that the distinctions between levels of buddhahood do not have anything to do with differences or levels in one's own benefit but rather an ever-increasing magnitude of ability to spontaneously benefit others, which again is like splitting hairs for us because any level of buddha activity is inconceivable. Anyway, I doubt I could possibly say anything more on the subject.